Dyeing of textile materials by the use of light-sensitive diazo salts



I Patented Jan. 9, 1951 DYEING or" TEXTILE MATERIALS BY THE UsE orLIGHT-SENSITIVE DIAZO SALTS Sam Charles Slifkin, Binghamton, N. Y.,assignor to General Aniline & Film Corporation, New York, N. Y., acorporation of Delaware No Drawing. Application August 18, 1945,

Serial No. 611,440

9 Claims. (01. 95-6) The present invention relates to an improvedproccssfor-the printing of designs upon textile materials and the likeand to the product thus obtained. The invention also comprehends as anew article of manufacture textile materials prepared to be printed inaccordance with the process or the present invention.

Ordinarily, textile materials are printed from an intaglio rollercarrying a dyestuff paste, which transfers the paste in the design to bereproduced to the cloth which is then suitably treated to develop or fixthe dye. The printing of textiles in this manner involves the expense ofpreparing the intaglio roller, usually from a drawing, by anelectroplating or etching process, which is slow, requires great skilland is costly. Furthermore, the production of gradated designs in thismanner or by other mechanical means is limited because of the practicaldifiiculty in preparing a printing roll and the properties of the dyepreparations employed. Another disadvantage of this method of printingresides in the fixed dimension of the roll, which limits the spacing orreproduction frequency of the design upon the cloth.

Heretofore, it has been proposed to produce photographic images uponpaper impregnated or coated with certain light sensitive diazo compoundsand couplers. While such processes have been reasonably satisfactorywhen applied to coated paper, when applied to textile materials, theprints show poor gradation, poor density and frequently have poorcontrast, poor wash fastness and poor color fastness, and have not beensufficiently satisfactory to compete with the intaglio printing ofdesigns upon textiles.

It is an object of the present invention to provide a process of dyeingand p in il materials and the like to produce designs having goodgradation and good wash fastness.

Another object is the provision of a textile material treated with alight sensitive composition upon which may be reproducedphotographically various designs and pictures by a simple process.

Another object of the invention is the provision of a process for theproduction of colored designs upon textile materials which does notrequire the use of engraved printing rolls and the like for applying thedesign to the fabric.

Still another object of the invention is the production of designs upontextile fibers in colored patterns having good wash fastness.

Another object is the provision of a process for overall dyeing oftextile materials with the production of a light discharged pattern orde- Si In accordance with the present invention, textile material ofnatural or synthetic fibers or materials impregnated with a lightsensitive composition comprising a light sensitive diazonium compound ofan aromatic amine decomposable.

by light to form a non-coupling compound, an organic compound couplingin alkaline medium. precoupling preventive compound or compounds andzinc chloride, is exposed to light under a pattern, design orphotographic film to be reproduced and is then developed by a suitablealkaline treatment. There is thus reproduced on the textile material apositive image showing excellent gradation and density.

The presence of zinc chloride reduces yellowing of the burned out areas,improves the coupling rate of the azo components and induces thedevelopment of rich tones due to color saturation of the fiber. Thepresence of zinc chloride is of particular value in printing on cottoncloth of coarse texture, or upon certain regenerated celluloses, and mayalso be employed in some cases, in printing on cellulose acetatetextiles or textiles made from other organic derivatives of cellulose. Alarge quantity of zinc salt will, in some cases. impart a stiffness orhand to the cloth. However, the hand of the cloth may be improved bywashing. In printing on cotton cloth of coarse texture, improved resultsare obtained by the use of the zinc salts. In addition to improvingradation and density of the print, a desirable brightness of color isimparted thereto. In the dyeing of cotton cloth by the presentinvention, the addition of zinc chloride in amounts of from 5 to about10% exclusive of any required for forming a salt with the diazoniumcompound is distinctly beneficial and results in finely gradated prints,as distinct from the contrasty prints preferred in the reproduction ofmechanical drawings, an improved color saturation of the fibers, and animproved brightness or brilliance of color. In addition, when blue colorforming azo components are employed a distinct shift in shade toward thegreen is produced. In the dyeing of cloth of regenerated cellulose orcellulose acetate, similar beneficial results are obtained, although insome cases a stiffening of the cloth is encountered. This may beimproved by after washing, or by the use of lesser amounts of zincchloride employed, although in the latter case, some loss of colorsaturation and color brilliance may be encountered. The addition of athiocarbonic acid compound, such as, for example, thiourea,phenylthiourea and the like, which is a part of the present invention,is beneficial as it decreases the the air and a valved conduit foradmitting ammonia vapor, and the development is carried out by placinthe bolt of cloth therein, closing the apparatus, exhausting the air andintroducing gaseous ammonia containing a suitable proportion of watervapor. The ammonia preferably is introduced under pressure, withconcurrent or subsequent heating of the apparatus to a suitabletemperature. pressure, the ammonia is caused to penetrate into the boltof fabric and cause proper and complete development of the printeddesign.

For printing cloth in small pieces the commercially available diazotypemachines may be employed. Such machines, employing a transparentrotating cylinder with a central light source also may be employed toprint a recurrent pattern, by applying to the transparent cylinder atransparent sheet or pellicle carrying an opaque or grauated design tobe reprouuceu and feeding the cloth to the rotating cylinder at asuitable speed.

The present invention enables the printing of textile materials in avariety of colors with a contrasty or gradated design in white or othercolors. It is thus possible to obtain, for example, a design in acolored field, which shows a fineness of gradation not heretoforeobtained on fabrics or textiles by the intaglio roll method or by otherprocedures heretofore employed. Furthermore, in the reproduction ofnon-gradated designs, the present method obviates the expense ofpreparing intaglio rollers, silk screens and the like, as drawings ordesigns to be reproduced can be made on transparent sheet materialdirectly usable as the original. Where a gradated design is desired thiscan conveniently be obtained by photographing the subject on a silverhalide film which is developed by the reversal process or isrephotographed to produce a transparent positive of the original. Forcontinuous printing the design may be on a transparent belt or cylinder,and especially in the former case practically any spacing desired can beprovided between the'designs.

Cloth impregnated or prepared with the photoprinting composition of thepresent invention may be stored for relatively long periods withoutsubstantial deterioration, for use as required and may be printed insmall or large yardage, as desired, at a faster rate and with lessexpense than hand or machine printing processes previously employed.

Preferably, the cloth to be printed is not sized and in making up thephotoprinting composition for application thereto, it is preferred toavoid thickening agents which would limit penetration of the compositioninto the fibers. Thus, in the case of some thin fabrics the design willappear obverse upon the reverse side of the cloth. Frequently it isdesirable to employ a wetting agent in the composition to effect uniformpenetration into the fibers and promote a level color in the field orbackground.

By employing ammonia under In general, to produce good gradation on cel=lulosic materials, it is preferred that the coupler employed is at leastequimolecularly equivalent to and preferably in excess of that requiredtheoretically to couple with the diazo compound. The degree of excesswill depend, among other factors, upon the kind of textile to beprinted, the particular kind of coupler, the action of stabilizing orother substances employed upon the fiber, the coarseness of the fiberand other factors. In general, the upper limit of the ratio of couplerto diazo compound employedin carrying out the invention will bedetermined in most cases by the solubility of the coupler in water. Aratio of 3 to 1 is not excessive in most cases and the ratio in manycases may go even higher. The excess of coupler results in improving thepenetration or substantivity of the azo dyestufi for the fiber, and alsocauses more complete coupling with consequent color saturation of thefibers.

The coupler and diazo compound generally are selected to produce an azodye having the desired wash fastness. The coupler selected for dyeing ofcotton, rayon or cellulose ester fibers preferably is free fromfunctional groups which can form amides, in order to obtain superiorwash fastness. However, in dyeing wool, silk, and other animal fibers,or so-called animalized fibers, or nylon the presence of sulfonic groupsor carboxy groups is desirable in some instances. The coupler also isselected with reference to its speed of coupling and the coupling energyof the diazo compound employed. It is preferred to employ slow couplerswith energetic diazo compounds, and more rapid couplers with lessenergetic diazo compounds, as by a proper selection the stabilizing ofthe composition against precoupling is facilitated. A diazo componenthaving a low coupling energy preferably is employed, as it is easier toprevent precoupling of such a diazo component, especially where acoupling component having high coupling energy is employed therewith.

I have found, in particular, that good results are obtained by employingas coupling components, the polyhydroxy compounds of the benzene andnaphthalene series which are free from amide forming functional groups,such as sulfonic or carboxy groups, although it will be understood theinvention is not limited thereto, as coupling components, containingsuch groups may be employed where less severe requirements aresatisfactory. Other suitable couplers which can be used in accordancewith the present invention are those having a reactive methylene group,such as the arylides of acetoacetic acid, and the various pyrazolone orpyrazolone carboxylic acid compounds or mixture of couplers may beemployed for producing special colors or effects. Examples of organiccompounds coupling in alkaline medium which may be employed-in carryingout the present invention are hydroxyaromatlc compounds such as7-hydroxy-l,2-naphthamidazole, 2 3-dihydroxynaphthalene. ethylenediamineamide of 2,3-hydroxynaphthoic acid, resorcinol, and organic compoundscontaining a reactive methylene grou such as 1-tolyl-3- methylpyrazolone, acetoacetanilide, acetoacetic acid benzylamide or otherpyrazolone compounds or arylides of acetoacetic acid. Or for producingtwo tone effects, as hereinafter described in detail, a mixture ofcouplers consisting of 2,3-dihydroxynaphthalene and m-hydroxyphenylureamay be used.

The following tabulation is illustrative of the color effects obtainablein accordance with the present invention by the use of couplers having areactive methylene group.

Coupler Diazonium Base Color acetoacetanilide p-diethylamino-m-toluidineorange. acetoacetic acid benzylap-ethylamino-o-toluidine. yellow.

mide. 1-tolyL3-methyl-5-pyrazop-diethylamino m ethyoxy deep red.

lone. aniline. l-tiolyHi-methyl-fi-pyrazop-aminodiphenylamine orange.

one.-

Other examples are given in the recipes below, but it is to beunderstood the enumeration of examples is illustrative and it is notintended to limit the invention thereto.

The preferred light sensitive diazo compounds are the homologousbenzenediazonium series having alkylamine or arylamine substituents inthe para-position. As examples of such preferred compounds, there may bementioned p-phenylaminobenzene diazonium sulfate, the zinc chloride orboron trifiuoride double salt of p-diethylamino-o-toluene diazoniumchloride, p-diethylamino-m-toluene diazonium chloride,p-ethylamino-o-toluene diazonium chloride,p-diethylamino-m-ethoxybenzene diazonium chloride, the zinc chloridedouble salt of p-diethylaminobenzene diazonium chloride, and the like.Aromatic diazonium compounds having hydroxy or carboxy watersolubilizing groups also may be employed,

although the dyed products obtained therefrom are less fast to washing.Examples of such compounds are zinc chloride double salt ofo-carboxy-p-diethylamino-benzene diazonium chloride and N-hydroxyethyl-N,n-butylaminobenzene diazonium chloride. Other light sensitivesalts of the diazonium compounds, such as, for example, the cadmiumchloride double salts and the like may be employed.

The present invention is applicable to the dyeing of various cellulosictextile. or felted materials such as bleached or unbleached cotton,mercerized cotton, rayon, cellulose ester fibers, nylon, silk, wool,vinyl chloride polymer fibers, casein fibers, leather, and the like.

Where a two color effect is desired the cloth may be preliminarily dyedor grounded with any suitable coloring material, and the photoprintingcomposition is then applied thereover and the cloth is exposed toactinic light under the desired pattern or matrix and developed. Ascoloring matters suitable for such preliminary dyeing of the cloth areknown to those skilled in the art, specific examples are not hererecited. Or, if desired, the composition of the present invention mayinclude any suitable light fast mordant or direct dye of any typewhereby the burned out areas are colored the shade of the direct dye,and the areas of lesser exposure are colored a composite color. Where amordant dye is employed the mordant used will be a metal salt compatiblewith the light sensitive composition, such as, for example, alum oraluminum sulfate. For example, a blue printed upon a yellow backgroundyields, upon exposure under a negative, a yellow design upon a greenishblue field, and a blue upon a red background yields a red design upon apurple to violet field. If a positive matrix is employed, the colorareas are reversed.

Dyeings in natural colors may be produced by treating the cloth firstwith a composition which upon exposure to actinic light under a suitablematrix or pattern and development will yield a design in one primarycolor, washing out excess composition, then treating the cloth with asecond composition which, upon exposure under a suitable matrix orpattern and development, will yield another primary color, washing outthe excess composition and then treating the cloth with a thirdcomposition which, upon exposure under a suitable matrix or pattern anddevelopment, will yield dyeings of a third primary color, it beingunderstood that suitably prepared patterns or matrices are employed, andproper registration of the design is secured.

Any suitable precoupling preventative known to the art may be employedin the composition of the present invention to stabilize the compositionand prevent coupling or deterioration during storage. Examples of suchprecoupler preventatives which are suitable for use in accordance withthe present invention are citric acid, a mixture of citric, boric andphosphoric acids, tartaric acid, alpha-beta unsaturated aliphatic acids,naphthalene polysulfonic acids and the like. In addition, thecomposition produced in accordance with this invention may includesensitizers known to the art which increase the light sensitivity of thecomposition, anti-yellowing compositions, wetting agents and the like.

The addition of metal salts is also desirable in some instances to varythe shade. In general, certain metal salts improve the color saturationor density and in the case of blue dyeings shift the shade toward red.The dyeings, however, are frequently duller than those obtained whenzinc chloride is employed, and in some cases the burned out areas areyellowed or greyed.

The addition of small amounts of organic solvents, such as isopropylalcohol or ethyl alcohol frequently is desirable to increase the solu--bility of the diazonium compound or the coupler in the aqueous solution,and to improve the dyeings. Thus, for example, the dyeings on vinylchloride polymer fibers are improved by the addition of alcohol, not inexcess of about 5%. as greater concentrations tend to matte the threadsand produce an increased stiffening of the cloth, which however, is notan important disadvantage for many uses. Excessive amounts of zincchloride also should be avoided in dyeing Vinyon".

The thickness of the fibers in woven and knitted textiles affects thequality of the dyeings. In general, heavier or thicker threads,especially of the more opaque cellulosic fibers, such as cotton or linengive more contrasty prints lacking in detail, while thinner fibers givebetter gradation. However, the more transparent fibers, such as rayonsand cellulose esters yield dyeings showing better gradation and detailwhich is less adversely affected by size of thread than in the case ofmore opaque threads.

The invention will be described in greater detail in connection with thefollowing specific examples, which are given to illustrate preferredembodiments of the invention:

Example 1 An aqueous solution of the following composition was preparedand applied to a cloth of eel lulose acetate.

0.5% zinc chloride double salt of diazotized pdlethylamino-o-toluidine(.0019 mol) of the following formula:

CaHl

CIH. H:

0.8%, 2,8-dihydroxynaphthalene (.005 moi) 5% citric acid 5% zincchloride .0l% saponin (approx.)

After drying, the cloth was exposed under a film carrying a photographand developed in an atmosphere of ammonia at an elevated temperature.The cloth was dyed a bright blue showing excellent gradation in thephotograph and of good fastness to washing.

Example 1a If, in the above example, one percent of the diazoniumcompound is employed, the fastness to light of the dyed cloth isimproved.

In place of cellulose acetate cloth in the above examples, a cloth ofbatiste, regenerated cellulose, of the xanthate or viscose type, ballooncloth, knitted rayon jersey, or of mixed cotton and rayon may besimilarly dyed.

Example 2 By replacing the dihydroxynaphthalene coupler in Example 1, by2% of 7-hydroxy-1,2-naph thimidazole (.10 moi) and proceeding asdescribed in Example 1, a red dyeing is obtained on cloth which is ofgood wash fastness.

Example 3 By replacing the dihydroxynaphthalene coupler in Example 1 by0.5% of resorcinol (.055 mol), a sepia dyeing is obtained of good washfastness. However, on some grades of cellulose acetate, the white areasremain somewhat discolored.

Example 4 By replacing the diazonium compound in Example 1 by .5% of thezinc chloride double salt of diazotized p-diethylamino-o-phenetidine ofthe formula:

/N NH: CzHs U CaH;

and proceeding as in Example 1, a dyeing of a greenish shade withslightly less color saturation is obtained. The wash fastness is good.

Example 5 By replacing the diazonium compound in Example 1, by 0.5% ofp-phenylaminobenzene diazonium sulfate, dyes are obtained of a reddershade than in Example 1 and which show less gradation, that is, they aremore contrasty.

Example 6 By proceeding as described in Example 1, em-

benzene diazonium chloride in the form of the zinc chloride double salt,and as coupler, 7-hydroxy-1.2-naphthimidazoie, with the addition of 5 to10% of thiourea, particularly good red dyeings are obtained. Theaddition of thiourea is desirable for it increases the brilliance of thecolors and decreases the hand of the cloth.

Example 8 By employing in Example 1 as the coupler the hydrochloride ofthe ethylene diamine amide of 2,3-hydroxynaphthoic acid, dull greendyeings of good wash fastness are obtained with the white areasdiscolored due to the formation of colored products with ammonia, whichdiscoloration can be washed out.

Example 9 By replacing the diazonium compound in Example 1 by 1% of zincchloride double salt of diazotized p-ethylainino-m-toluene diazoniumchloride, and proceeding as in Example 1, a dyeing of a purplish blueshade of good density and good resistance to fading is obtained.

Example 10 An aqueous solution of the following composition is preparedand applied to a cloth of cellulose acetate. Parts are by weight.

3 parts p-phenylaminobenzene diazonium sulfate 5 partsm-hydroxyphenylurea 0.05 part 2,3-dihydroxynaphthalene 10 parts citricacid 5 parts zinc chloride 0.01 part saponin 7.9 parts isopropyl alcoholparts water After drying the cloth is exposed to a suitable source oflight under a photograph exhibiting portions in full densities andportions in highlights or partial densities, and developed in anatmosphere of ammonia at an elevated temperature. The cloth exhibited agreen color in those areas corresponding to full densities of the matrixand grey in the areas corresponding to highlights.

It will be understood that various modifications may be made in theinvention described in the above examples without departing from thespirit or scope of the invention.

I claim:

1. A light sensitive element comprising a textile fabric impregnatedwith a light sensitive diazo compound decomposable by light to form anoncoupling compound, an organic compound coupling in alkaline medium, aprecoupling stabilizer, and zinc chloride the latter being in amounts offrom 5 to about 10% exclusive of any required to form a complex saltwith the diazonium compound.

2. A light sensitive element comprising a textile fabric impregnatedwith a light sensitive diazo compound decomposable by light to form anoncoupling compound, a hydroxyaromatic coupler in molecular excess, aprecoupling stabilizer, and zinc chloride the latter being in amounts offrom 5 to about 10% exclusive of any required to form a complex saltwith the diazonium compound.

3. A light sensitive element comprising a regenerated cellulose textilefabric impregnated with a light sensitive diazo compound decomposable bylight to form a non-coupling compound, an organic compound coupling inalkaline medium, a precoupling stabilizer and zinc chloploylni as thediazo compound. p-dietliyiamino- 1 ride the latter being in amounts offrom 5 to about 10% exclusive of any required to form a complex saltwith the diazonium compound.

4. A light sensitive element comprising a textile fabric of polymerizedvinyl chloride impregnated with alight sensitive diazo compounddecomposable by light to form a non-coupling compound,

an organic compound coupling in alkaline medium, a precouplingstabilizer, and zinc chloride the latter being in amounts of from toabout exclusive of any required to form a complex salt with thediazonium compound.

5. A light sensitive element comprising a cotton textile fabricimpregnated with a light sensitive diazo compound decomposable by lightto form a non-coupling compound, an organic compound coupling inalkaline medium, a precoupling stabilizer, and zinc chloride the latterbeing in amounts of from 5 to about 10% exclusive of any required toform a complex salt with the diazonium compound.

6. A light sensitive element comprising a, textile fabric impregnatedwith a light sensitive diazotized p-alkylaminearylamine decomposable bylight to form a non-coupling compound, a hydroxyaromatic coupler, aprecoupling stabilizer, and zinc chloride the latter being in amounts offrom 5 to about 10% exclusive of any required to form a complex saltwith the diazonium compound.

7. A light sensitive element comprising a textile fabric impregnatedwith a light sensitive metal halide salt of a diazotizedp-alkylaminearylamine decomposable by light to form a noncouplingcompound, 2,3-dihydroxynaphthalene, a precoupling stabilizer, and zincchloride the latter being in amounts of from 5 to about 10% exclusive ofany required to form a complex salt with the diazonium compound.

8. A light sensitive element comprising a textile fabric impregnatedwith a, light sensitive diazo compound decomposable by light to form anon-coupling compound, an organic compound coupling in alkaline medium,a precoupling stabilizer, zinc chloride the latter being in amounts offrom 5 to about 10% exclusive of any required to form a complex saltwith the diazonium compound, and a direct dyestuil'.

9. A light sensitive element comprising a colored textile fabricimpregnated with a light sensitive composition capable of development toa different color and comprising a light sensitive diazo compounddecomposable by light to form a non-coupling compound, an organiccompound coupling in alkaline medium, a precoupling stabilizer and zincchloride the latter being in amounts of from 5 to about 10% exclusive ofany required to form a complex salt with the diazonium compound.

SAM CHARLES SLIFKIN.

REFERENCES CITED The following references are of record in the file oi.this patent:

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1. A LIGHT SENSITIVE ELEMENT COMPRISING A TEXTILE FABRIC IMPREGNATEDWITH A LIGHT SENSITIVE DIAZO COMPOUND DECOMPOSABLE BY LIGHT TO FORM ANONCOUPLING COMPOUND, AN ORGANIC COMPOUND COUPLING IN ALKALINE MEDIUM, APRECOUPLING STABILIZER, AND ZINC CHLORIDE THE LATTER BEING IN AMOUNTS OFFROM 5 TO ABOUT 10% EXCLUSIVE OF ANY REQUIRED TO FORM A COMPLEX SALTWITH THE DIAZONIUM COMPOUND.